1. Field of the Invention
This invention relates to a wireless communication device capable of interfacing with a base station of a service provider and intended for occasional use without requiring a subscription with the service provider. The device of the invention is particularly adapted to use a non-rechargeable replaceable battery having associated therewith an encoded identification code which includes payment information, such as prepayment of a certain calling time and/or an ID code for account tracking purposes.
2. Description of Related Art
Conventionally, wireless communication devices are set up to communicate with the ground stations operated by a service provider selected by the subscriber by entering into a long-term contractual relationship with the service provider extending over a time period of not less than usually one year. Cancellation of the service agreement prior to the time period agreed to will result in substantial monetary penalties. In addition, the subscriber is assigned a telephone number having commonly the same area code as the wireline telephone service provided to the subscriber's residence or business. This telephone number and other ID codes associated with the wireless communication device allow the subscriber to initiate and to receive telephone calls from any subscriber connected to the public switched telephone network (PSTN).
Although a large number of subscribers to the wireless phone service will use their device for both initiating and receiving calls and therefore require a conventional telephone number, there are other subscribers and many potential subscribers who may want to use their wireless communication device only occasionally or for emergencies and do not intend to receive incoming calls. These other subscribers may agree to a one time purchase of a wireless communication device at a reasonable cost and may subsequently want to purchase a certain amount of prepaid calling time, for example in the form of a certain number of time units, for just such occasional use.
In addition, wireless communication devices almost exclusively use rechargeable batteries to provide power to the device. Rechargeable batteries are known to provide the relatively large current required for transmitting signals, but are also known for not being able to retain their charge over extended periods of time. In a wireless communication device intended for occasional use, it could therefore be anticipated that the subscriber may not be diligent in maintaining the rechargeable battery in its charged state, thereby preventing the wireless phone from operating properly when needed.
Emergency wireless phones and wireless phones with a limited calling time are known in the art. WO 96/03001, for example, shows a wireless phone wherein removal of a sealing means allows the phone to be switched on and the simultaneous transmission of an ID code to the telephone exchange enables access to a predetermined telephone line for a restricted period of time. The user does not need a subscription contract. U.S. Pat. No. 5,138,650 shows a wireless phone having memory means for storing a credit balance prior to usage of the phone and means for updating the credit balance. The phone can be used as long as there remains a credit balance. GB A 2 262 685 describes a wireless phone device where radio transmission from the device can be terminated either by receiving a remote termination signal or after a predetermined length of time which is determined at the time of purchase of the device or its manufacture.
The wireless communication devices described above are either intended to be disposable after expiration of the preprogrammed connect time which is rather expensive considering the manufacturing cost of a wireless communication device, or the accounting data are managed and updated by the service provider. Therefore, there is a need for a wireless communication device for occasional use which can be purchased and operated reliably and inexpensively and which does not require a subscription contract to be in force with a service provider at all times.
It is therefore an object of the invention to provide a wireless communication device with a non-rechargeable replaceable battery with an extended shelf-life and an adequate battery capacity which exceeds a certain predetermined, preferably prepaid calling time. It is a further object of the invention to have a unique ID number assigned to the battery which can be processed by a service provider and indicates a prepaid amount of calling time. The usage of the phone is allowed as long as there is a credit remaining for the unique ID number; a new battery with a different unique ID number can be inserted into the wireless communication device to continue the call or to initiate other calls.